Exercise and Immunity

Question 1

What are B cells?

Answer 1

white blood cells that make infection-fighting proteins called antibodies

Question 2

What are T cells?

Answer 2

fight foreign invaders, produce cytokines (activate other parts of the immune system), present antigens to B cells

Question 3

Antigen def.

Answer 3

Substances found on cells (both foreign and in-born) that allow your immune system to recognize them

Question 4

Antibody def.

Answer 4

proteins produced by B cells that bind to and destroy pathogens

Question 5

Physical barriers

Answer 5

skin, tears, mucous membranes, epithelial surfaces, eyelashes (body hair)

Question 6

Chemical barriers

Answer 6

low stomach pH, urination, tears (lysozymes -> enzymes), salivary enzymes, vaginal secretions

Question 7

Leucocytes

Answer 7

any white blood cell that is a part of the immune system

Question 8

Pathogen def.

Answer 8

any organism or substance capable of causing disease

Question 9

Explain the J curve

Answer 9

• Y -> risk of infection [low to high]
• X -> exercise intensity [low to high]
• Moderate exercise improves immunity excessive amounts cause impaired immunity
• Curve named after its shape
• Reason for curve:
  ○ Lower leucocyte numbers due to stress
  ○ Inflammation from muscle damage
  Exposure to air born bacteria and viruses (increased rate and depth of breathing)

Question 10

How can you minimize the risk of infection?

Answer 10

• Sufficient recovery time
• Avoid contact with infected people
• Oral hygiene
• Hydration
• General good hygiene
• Suitable and varied diet Sufficient sleep

Question 11

Plasma concentration of hormones

Answer 11

Adrenaline - Lymphocyte subpopulations and cytotoxic activities
GH - mediate acute effects of exercise on neutrophils
Cortisol - maintaining lymphopenia (low level of lymphocytes) and neutrophilia

Question 12

Name 3 mechanisms of the adaptive immune system

Answer 12

Lymphocyte production, Antibody production, Temperature increased

Question 13

3 mechanisms of the innate immune system

Answer 13

Inflammation, clotting, leucocytes (innate immune system), chemical barriers, physical barriers

Question 14

Summarise how the body reacts to pathogens

Answer 14

• Body recognizes a foreign antigen and the pathogen is ingested by a macrophage.
• Macrophage displays the antigen for that particular pathogen and antigen signals a helper T-cell.
• T-cell reads this signal and sounds the alarm for other parts of your immune system to respond.
• B-cell responds to this call and comes to read the antigen from the surface of the macrophage.
• B cell then becomes activated by T-cell and produces millions of antibodies that are specific to the antigen. These antibodies are released into your body to attach to the virus particles.
• Antibodies then send a signal to other macrophages and other immune cells to come and engulf and destroy the pathogen.
• Once the number of invaders has dropped significantly and the infection has resolved, suppressor T-cell will signal the other cells of the immune system to rest. This is important as prolonged activation of your immune response could eventually lead to damage to your healthy cells
  Memory B & T cells persist in the body to quickly produce antibodies to subsequent infection by pathogens expressing the same antigen.

Question 15

What are the roles of the cells in the Innate Immune system?

Answer 15

Macrophage - ingest and degrade cells (endocytosis), signal other cells using (cytokines)
Neutrophil - secrete factors that kill and degrade pathogens
Dendritic cell - capture, process, and present antigens to activate T cells
Basophil - release histamine and other inflammatory mediators in response to allergens or infections (allergic reactions)
Eosinophil - combat parasitic infections and modulating allergic responses (toxic granules and cytokines)